Well, as this is about Ireland, EU regulations state that a drone operator may control just a single drone at a time. (So, no simultaneous control.)

*) UAS.STS-01.040 Responsibilities of the remote pilot: "(d) shall operate only one unmanned aircraft at a time"

https://www.easa.europa.eu/en/document-library/easy-access-r...

How the hell can a single operator pilot 20 at the same time. These aren't uavs, let alone uavs with the ability to navigate congested airspace!